Brainteaser: Tool ID

Every time we give a tour of the Conservation Lab, we pull out our Mystery Tool, in hopes that someone will be able to identify it. As with some other items in the lab, the reason we have this particular gadget has been lost in the mists of time. It measures 5.5″ from tip to end, and 1.25″ at its widest point. The cylindrical shaft has a flat side, suggesting that it is intended to fit into some kind of machine. Please post a comment if you have any idea what this strange little tool might be. If you’re comment-averse, you can email us at tedone@iastate.edu.